Thank's for answer Ken:
you are right, it could kill battery on laptop, but it's very "confortable" keep it on hybernate and forget to backup manually each day.
If a service can wake up during night and in 1 hour can make copy of changed file (shadow copy do it already).
I think today's laptop battery can survive until end of job without problem so week; in this way i can leave laptop on bag and forget it.
On business day if i need laptop, i charge it during work; if not, it will wakeup during night for some minute (because there isn't anything new to backup) and return to "sleep"
immediately.
If someone inside whs team can read this post, i think could be a good feature to develop.
Thanks